1. Field of the Invention
The present invention relates to an improved hose for use in motor vehicles, and more particularly, to a hose for use in transmission systems of motor vehicles.
2. Description of the Prior Art
Three-, four, and five-layer hoses are known to be used in the transmission system of motor vehicles. An inner layer is in direct contact with the fluid to be transported through the hose. An outer layer is a protective covering which also strengthens the hose. One or more layers located between the inner and outer layers provide reinforcing strength to the hose.
When choosing materials for a transmission hose, a number of considerations must be balanced against one another. The transmission hose must be able to withstand the elevated temperatures of the transmission fluid for long periods of time. The slower the transmission hose is xe2x80x9cagedxe2x80x9d by the heated transmission fluid, the longer the useful life of the hose. A transmission system typically relies on hydraulic forces to carry out its function, thus leading to the need for transmission hoses to be able to withstand high pressures. A transmission hose must also be flexible so that it can be placed in the motor vehicle where convenient for the manufacturer. Other considerations include the amount the hose ages during storage, processing characteristics, and manufacturing costs.
In an effort to meet the aforementioned considerations with respect to improving the life and operating characteristics of pressurized flexible hose, a number of elastomers and rubbers have been used, such as ethylene propylene rubber, butyl rubber and polychloroprene rubber. While certain such elastomers and rubbers are usable with petroleum base fluids and others are usable only with non-petroleum base fluids, these elastomers age during storage and use, often can not be used with a wide range of fluids of various chemical composition, and may rapidly deteriorate at elevated temperatures.
Accordingly, there is a need to provide an improved fuel hose which has low impermeability and high flexibility while also being inexpensive to manufacture.
The present invention is a three-layer transmission hose for use in a vehicle, which includes a reinforcement layer sandwiched between an inner layer and an outer layer in which one or both layers are made of a blend of a poylethylene/vinylacetate (EVM) and a chlorinated polyethylene (CPE).